|
These devices can be attached to a computer or
video device just as you would connect a traditional monitor.
The term "big screen" is used to indicate a TV
size larger than 40 inches in diagonal measurement. Until recently these are
usually rear-projection screens, although we are seeing more and more flat-panel
displays at competitive prices.
The appeal of Rear-Projection TV (RPTV)
There certainly is a great deal of consumer
appeal for RPTVs these days. And it's easy to understand. Part of it is due to
the simplicity of the product. After all, what could be easier than getting a
bigger TV? If you want a larger image with no muss and fuss, it can be purchased
from any local big-screen retailer and delivered within a day or two.
Another the appeal of RPTVs is the impression
created by big-screen retailers that RPTVs are cheaper than front projection
systems.
Clearly there is a market for both types of
home theatre solutions. From a practical perspective your room size has a lot to
do with determining which approach is best for you. If you don't have a large
viewing room, a 40" to 60" diagonal TV will probably be plenty. In this case,
the rear-projection solution is more practical assuming you can fit the box into
the space.
But if you want the large screen cinema
experience and your room size will allow it, front projection is the way to go.
Front projectors are made to produce screen images in the range of 70" to 120"
diagonal or more. Once people realize they can get a picture up to four times
the size for the same money as a good RPTV, it opens up a whole new world of
entertainment possibilities.
How good is the Rear-Projection TV:
As noted above, the advantages of RPTVs are
obvious. There is a wide array of products in different sizes and price ranges.
There are usually several local showrooms in most areas. And they are simple to
buy and install. However, RPTVs have several limitations that front-projection
systems do not. Among them are limited screen size, poor viewing angles,
excessive reflections, poor aspect ratio management, and loss of floor space.
Screen size is an obvious difference, but still
worth thinking about for a moment. A 100" diagonal front projection screen is
four times the surface area of a 50" RPTV. If you want to put real "theatre" in
your home theater, the projector and movie screen approach delivers it. RPTVs
are just big televisions.
Digital Projectors
A digital projector is an electro-optical
machine which converts image data from a computer or video source to an image
which is then displayed on a distant wall or screen using a lens system. A
typical resolution for a portable projector will be the SVGA standard (800×600
pixels), with more expensive devices supporting XGA (1024×768 pixels). The cost
of a device is not only determined by its resolution, but also by its
brightness. For use in large conference rooms the brightness should be between
1,000 and 4,000 ANSI lumens.
There are four competing digital projection
technologies: high intensity CRT, LCD projectors using LCD light gates, Texas
Instruments' DLP technology and LCOS or liquid crystal on silicon. In 2004 and
2005, LCD front projection has been enjoying a come-back because of the addition
of the dynamic iris which has improved contrast up to the levels of DLP.
There is a genuine market for both RPTVs and
projectors for home theatre. RPTVs are simple, but they have limitations in
screen size and performance. Projectors and screens require some installation
work, but once it is done you end up with a more dramatic theatre experience.
The bottom line is this: if you are looking at
digital RPTVs and your viewing room can accommodate a 90" or 100" screen, don't
overlook the possibility of a projector and screen instead. If you can afford a
digital RPTV, you can afford a projector. And dollar for dollar the projector
will often deliver the maximum "wow" factor for the money invested.
|
